This invention relates generally to the field of wheelchairs, and more particularly to the field of wheelchair and vehicle entry systems where operative means are provided for the wheelchair to be taken or loaded into the vehicle. More particularly, the invention relates to such systems where the seat component of the wheelchair is detachable from the wheeled carriage component, such that the seat component becomes the vehicle seat for the user, and where entry into the vehicle is fully automated such that the user can independently and without assistance make entry into the vehicle, position and secure the seat component in the vehicle, load the carriage component into the vehicle, ride in or drive the vehicle, unload the carriage component, and exit the vehicle onto a wheelchair for external mobility.
Disabled individuals having limited or complete loss of their ability to walk or stand, but who otherwise retain full or partial use of their upper body and arms, can utilize self-propelled or powered wheelchairs for mobility. Typical wheelchairs comprise a seat permanently attached to a wheeled frame or carriage usually comprising a pair of larger rear wheels for stability and propulsion efficiency and a pair of smaller front wheels for directional guidance. Wheelchairs may be manually powered, whereby the user grips and rotates the large rear wheels to move the chair in the desired direction, or may be propelled by power means, such as a battery-powered electric motor used to rotate the wheels. Wheelchairs are commonly constructed to be collapsible for easier storage, such that the wheelchair can be put into a vehicle trunk, placed onto an external rack, or loaded into the interior of a van after the user is positioned in the seat of a vehicle. In most instances, a wheelchair user requires the assistance of another person for entry into and exit from a vehicle, either in terms of physically transferring the user from the wheelchair into the vehicle or from the vehicle to the wheelchair, or in terms of loading the empty wheelchair itself into the vehicle after the user is situated in the vehicle and then unloading the wheelchair for use at the destination, or both. This often requires a significant amount of time and effort, and in the case where the disabled individual is larger than the assisting person or when the disabled person has limited upper body strength, can be a very difficult task.
Attempts to address the problem have primarily been directed to providing powered lift means or ramps on larger vehicles such as vans, whereby the occupied wheelchair can be lifted or rolled into the vehicle and then secured in place, without requiring the user to exit or be removed from the wheelchair. The height of common wheelchairs in use usually requires vans to be adapted by raising the roof and/or lowering part of the floor to accommodate the height of the wheelchair and occupant, and usually requires the structural integrity of the vehicle to be compromised by cutting into the chassis or other framing components, moving the gas tank, relocating wires, etc. Alternatively, the wheelchair may be constructed with collapsible or retractable wheels such that its overall height is reduced when placed into the vehicle, but this wheelchair construction is less stable and precludes wheelchairs with large power components. Another strategy has been to construct wheelchairs in a manner whereby the seat component is detachable from the wheeled carriage component. Receiving means are provided in the vehicle such that the seat component can be transferred into the vehicle, with the carriage component loaded separately. The invention at hand takes this approach to the problem, but improves over the designs currently known.
Examples of systems where the entire wheelchair is lifted into the vehicle are given in U.S. Pat. No. 4,456,663 to Hems et al., U.S. Pat. No. 4,661,035 to Danielsson, U.S. Pat. No. 5,466,111 to Meyer, and U.S. Pat. No. 6,416,272 to Suehiro et al. In Hems et al. ""663, Danielsson ""035, and Suehiro ""272, a mounting arm is swiveled outward from the door opening. The wheelchair is attached to the mounting arm and the wheels are raised, such that the wheelchair can be pivoted into the vehicle. In Meyer ""111, the wheelchair is connected to mounting means on the inside of the vehicle door and the wheels are raised. Closure of the door orients the wheelchair properly in the vehicle.
Examples of ramps specifically designed to provide vehicle entry and exit means for a wheelchair are shown in U.S. Pat. No. 4,084,713 to Rohrs et al., U.S. Pat. No. 5,259,081 to Henderson, and U.S. Pat. No. 5,871,329 to Tidrick et al. The ramps are intermediately hinged such that they can be vertically oriented in a folded configuration when retracted. The user advances the wheelchair up the ramp to a space in the vehicle. The ramp is then folded to fit within the vehicle.
The alternative solution of providing a wheelchair having a chair or seat structure detachable from the wheeled carriage structure is shown in U.S. Pat. No. 3,865,427 to Delany, U.S. Pat. No. 4,643,446 to Murphy et al., U.S. Pat. No. 4,728,119 to Sigafoo, U.S. Pat. No. 5,110,173 to Megna, and U.S. Pat. No. 5,674,041 to Smith, Jr. et al. In Deleany ""427, the seat structure is provided with rollers which allow it to be transferred to a track mounted in the vehicle door, such that the seat structure is properly positioned in the vehicle when the door is closed. In Antonellis ""791, the seat portion detaches and slides onto a pair of parallel tracks disposed on the vehicle seat. The Murphy et al. ""446 and Sigafoo ""119 devices are wheelchairs where the rear wheels and main frame portion are removed from the front wheels and seat portion, with the seat portion placed onto the vehicle seat. Megna ""173 sows a detachable seat structure which slides onto a pair of tracks which are part of a support structure built into the vehicle. Smith, Jr. et al. ""041 shows a detachable seat structure which slides over and is placed onto the vehicle seat.
It is an object of this invention to provide in combination a wheelchair and a vehicle entry and exit access system for individuals having limited or total loss of the use of their legs, but who retain upper body and arm functionality, such that the wheelchair user is able to independently and without assistance make entry into the vehicle using a retractable ramp assembly and runway, position and secure the detachable seat assembly component of the wheelchair in the vehicle for use as a vehicle seat during vehicle transport, automatically retract the ramp assembly while loading the carriage assembly component of the wheelchair into the vehicle, ride in or drive the vehicle while seated in the seat assembly component, automatically deploy the ramp assembly to unload the carriage assembly component upon arrival at the destination, and exit the vehicle by releasing the seat assembly component, traveling the runway to the ramp, rejoining the seat assembly component onto the carriage assembly component forming the complete wheelchair for external mobility, and moving down the extended ramp. It is a further object to provide such a system which can be incorporated in the vehicle during initial manufacture or retrofitted at a later date without the necessity of altering in negative manner the structural integrity of the vehicle. It is a further object to provide such a system wherein the seat assembly component of the wheelchair may be adapted from a standard vehicle seat manufactured by the vehicle manufacturer.
The invention comprises a wheelchair vehicle access system for a motorized vehicle such as a van, wherein the wheelchair is comprised of a chair or seat component or assembly mounted on castors, rollers or the like, and which is detachably connected to a wheeled carriage component or assembly, the seat preferably being an original equipment manufacturer (O.E.M.) vehicle seat for a given make of van. A folding ramp is connected to the vehicle such that it can be automatically extended through the open vehicle side door to contact the ground for entry to and exit from the vehicle, and which can be automatically retracted into a folded configuration for compact storage when the vehicle is in use. The ramp is provided with locking means to receive the wheelchair in a manner which locks the wheelchair carriage assembly to the ramp when the wheelchair is rolled or driven up the travel surface of the ramp. The high end of the travel surface of the ramp is positioned lower than the floor of the vehicle when the ramp is extended, with the ramp further comprising a bridge member which is positioned above the travel surface of the ramp at a height even with the vehicle floor and even with the upper surface of the carriage assembly. With the seat assembly released from the carriage, the seat assembly may be rolled from the upper surface of the carriage assembly across the bridge member onto a runway disposed on the floor of the vehicle. The seat assembly is then rolled into the desired location in the vehicle and temporarily secured to the vehicle floor, either at the driver""s position or at a passenger position. The ramp is then retracted into the vehicle with the carriage assembly still attached thereto, such that both the ramp in the folded configuration and the wheelchair carriage assembly are disposed internally, and the vehicle door is closed. To exit the vehicle, the user automatically opens the door and extends the ramp to the ground. With the ramp fully extended, the carriage assembly is now in the proper position to receive the seat assembly. The seat assembly is released from the vehicle and rolled along the runway onto the secured carriage assembly. The seat assembly is locked to the carriage assembly and the carriage assembly is released from the ramp. After clearing the ramp, the ramp is automatically retracted into the vehicle and the vehicle door is closed. Preferably, means are provided to kneel or lower one corner or side of the vehicle in order to minimize the slope of the extended ramp.